Special thanks to Powerdoc (1st sample) and Tamron Europe (2nd sample) for providing this lens!

Introduction

The Tamron AF 200-500mm f/5-6.3 SP Di LD (IF) is a fairly recent addition to the small
gang of affordable 500mm tele zoom lenses with the other two members being the
Sigma AF 50-500mm f/4-6.3 APO EX and the Sigma AF 170-500mm f/5-6.3 APO. Surprisingly
none of the genuine manufacturers offers zooms in this range despite a surely
high popularity among amateur wildlife or sports photographers who just can't or don't want
to afford high-end fix focals in the 500mm league. Regarding its moderate price tag of
around 800 EUR/US$ the Tamron 200-500mm SP remains within reach of most mortals.

On an APS-C DSLR the field-of-view of the
Tamron resembles 320-800mm lens on classic (full-frame) SLRs. The numbers already
suggest to use either very high ISO settings or at least a monopod, better a tripod
in order to avoid blurred images.

The 200-500mm is a Di (Digitally Integrated) lens - this refers to a lens design
optimized for the special characteristic of today's image sensors. Nonetheless it's a
full-frame lens and perfectly usable on film SLRs as well. As an SP (Super Performance)
lens it is part of Tamron's designated professional grade lineup (similar to Sigma EX
or Tokina AT-X).

The optical construction is made of 13 elements in 10 groups including two LD (low dispersion)
elements. The lens features 9 aperture blades. The min. focus distance is 2.50m resulting in
a max. object magnification of ~1:5 at 500mm.
The lens has a size of 227x94mm with a total weight of 1237g inc. the detachable tripod
mount which is fairly compact for a lens in this range. The filter size is 86mm. Unlike
most other manufactures Tamron also spend some thoughts on how to use a polarizer with
attached hood (supplied) by implementing a rotatable filter thread (FEC ring).

As mentioned above the lens is member of Tamron's pro grade SP line-up and the build quality
is indeed very fine. The subjective quality of the used materials may not top notch
but thee lens feels very solid. Typical for all ultra tele zooms the lens extends quite
a bit towards the long end but there's virtually no wobbling of the inner lens tube.
The lens suffers a little from zoom creeping when tilting it up or down but there's
at least a transport lock which keeps the lens at its 200mm setting. It is interesting that
Tamron preferred to implement the focus ring next to the camera mount making it pretty
convenient to focus manually even at the 500mm setting. The lens has a conventional AF micro
motor which is surprisingly fast despite the big glass but a little bit on the noisy side.
In low light the EOS 350D had a tough time to AF at times - the rather slow max. aperture
takes its toll here. The focus ring rotates in AF mode which is a little dated by today's
standards.